FaceDetector无法检测到脸部

Question

I get the images from device camera:

public synchronized void  onPreviewFrame(byte[] data, Camera camera) {

    //Get image from data


}

Decode the images to RGB:

int[] rgb = decodeYUV420SPtoRGB(data, width, height);

RGB to Bitmap:

Bitmap bitmap = rgbToBitmap(rgb,width, height);

Print images in ImageView to make sure that conversion is fine:

iv.setImageBitmap(bitmap);

Detect num faces:

        FaceDetector faceDet = new FaceDetector(bitmap.getWidth(), bitmap.getHeight(), 1);
        Face[] faceList = new Face[1];
        int faces = faceDet.findFaces(bitmap, faceList);
        Log.e("NumFaces: ",faces + "");

Decode functions:

private  int[] decodeYUV420SPtoRGB(byte[] yuv420sp, int width, int height) {
    if (yuv420sp == null) throw new NullPointerException();

    final int frameSize = width * height;
    int[] rgb = new int[frameSize];

    for (int j = 0, yp = 0; j < height; j++) {
        int uvp = frameSize + (j >> 1) * width, u = 0, v = 0;
        for (int i = 0; i < width; i++, yp++) {
            int y = (0xff & (yuv420sp[yp])) - 16;
            if (y < 0) y = 0;
            if ((i & 1) == 0) {
                v = (0xff & yuv420sp[uvp++]) - 128;
                u = (0xff & yuv420sp[uvp++]) - 128;
            }
            int y1192 = 1192 * y;
            int r = (y1192 + 1634 * v);
            int g = (y1192 - 833 * v - 400 * u);
            int b = (y1192 + 2066 * u);

            if (r < 0) r = 0;
            else if (r > 262143) r = 262143;
            if (g < 0) g = 0;
            else if (g > 262143) g = 262143;
            if (b < 0) b = 0;
            else if (b > 262143) b = 262143;

            rgb[yp] = 0xff000000 | ((r << 6) & 0xff0000) | ((g >> 2) & 0xff00) | ((b >> 10) & 0xff);
        }
    }

    return rgb;

}
 public static Bitmap rgbToBitmap(int[] rgb, int width, int height) {
    if (rgb == null) throw new NullPointerException();

    Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.RGB_565);
    bitmap.setPixels(rgb, 0, width, 0, 0, width, height);
    return bitmap;
}

I get always 0 in Log.e("NumFaces: ",faces + ""); While I'm seeing in the imageView faces, real faces and faces in photos. I tried it with physical devices, 2.3 (bad camera) and 4.2 (good camera HD)

Edit: in 4.2 device I am getting 800x480 frames in onPreviewFrame.

Any idea what happens?

Answer 1

通过将设备水平而不是垂直握在手中，已经解决了该问题。